Also, could be that there is less Klingon content because there is less source material to use.

There is still a vast amount of unused Klingon canon content so I think you are being over-generous to Cryptic

The real reasons, I suspect, were (1) they had/have a finite amount of resources and understandably spent more of it doing Fed... they just over did that more than a tad (2) some very questionable early design decisions based on inconsistent management priorities during the development process